scholarly journals Rethinking immune checkpoint blockade: ‘Beyond the T cell’

2021 ◽  
Vol 9 (1) ◽  
pp. e001460 ◽  
Author(s):  
Xiuting Liu ◽  
Graham D Hogg ◽  
David G DeNardo

The clinical success of immune checkpoint inhibitors has highlighted the central role of the immune system in cancer control. Immune checkpoint inhibitors can reinvigorate anti-cancer immunity and are now the standard of care in a number of malignancies. However, research on immune checkpoint blockade has largely been framed with the central dogma that checkpoint therapies intrinsically target the T cell, triggering the tumoricidal potential of the adaptive immune system. Although T cells undoubtedly remain a critical piece of the story, mounting evidence, reviewed herein, indicates that much of the efficacy of checkpoint therapies may be attributable to the innate immune system. Emerging research suggests that T cell-directed checkpoint antibodies such as anti-programmed cell death protein-1 (PD-1) or programmed death-ligand-1 (PD-L1) can impact innate immunity by both direct and indirect pathways, which may ultimately shape clinical efficacy. However, the mechanisms and impacts of these activities have yet to be fully elucidated, and checkpoint therapies have potentially beneficial and detrimental effects on innate antitumor immunity. Further research into the role of innate subsets during checkpoint blockade may be critical for developing combination therapies to help overcome checkpoint resistance. The potential of checkpoint therapies to amplify innate antitumor immunity represents a promising new field that can be translated into innovative immunotherapies for patients fighting refractory malignancies.

Author(s):  
Allan Relecom ◽  
Maysaloun Merhi ◽  
Varghese Inchakalody ◽  
Shahab Uddin ◽  
Darawan Rinchai ◽  
...  

AbstractImmune checkpoint inhibitors provide considerable therapeutic benefit in a range of solid cancers as well as in a subgroup of hematological malignancies. Response rates are however suboptimal, and despite considerable efforts, predicting response to immune checkpoint inhibitors ahead of their administration in a given patient remains elusive. The study of the dynamics of the immune system and of the tumor under immune checkpoint blockade brought insight into the mechanisms of action of these therapeutic agents. Equally relevant are the mechanisms of adaptive resistance to immune checkpoint inhibitors that have been uncovered through this approach. In this review, we discuss the dynamics of the immune system and of the tumor under immune checkpoint blockade emanating from recent studies on animal models and humans. We will focus on mechanisms of action and of resistance conveying information predictive of therapeutic response.


2021 ◽  
Vol 9 (1) ◽  
pp. e001660
Author(s):  
Fatima Ahmetlic ◽  
Josia Fauser ◽  
Tanja Riedel ◽  
Vera Bauer ◽  
Carolin Flessner ◽  
...  

BackgroundAlthough antibodies blocking immune checkpoints have already been approved for clinical cancer treatment, the mechanisms involved are not yet completely elucidated. Here we used a λ-MYC transgenic model of endogenously growing B-cell lymphoma to analyze the requirements for effective therapy with immune checkpoint inhibitors.MethodsGrowth of spontaneous lymphoma was monitored in mice that received antibodies targeting programmed cell death protein 1 and cytotoxic T lymphocyte-associated protein-4, and the role of different immune cell compartments and cytokines was studied by in vivo depletion experiments. Activation of T and natural killer cells and the induction of tumor senescence were analyzed by flow cytometry.ResultsOn immune checkpoint blockade, visible lymphomas developed at later time points than in untreated controls, indicating an enhanced tumor control. Importantly, 20% to 30% of mice were even long-term protected and did never develop clinical signs of tumor growth. The therapeutic effect was dependent on cytokine-induced senescence in malignant B cells. The proinflammatory cytokines interferon-γ (IFN-γ) and tumor necrosis factor (TNF) were necessary for the survival benefit as well as for senescence induction in the λ-MYC model. Antibody therapy improved T-cell functions such as cytokine production, and long-time survivors were only observed in the presence of T cells. Yet, NK cells also had a pronounced effect on therapy-induced delay of tumor growth. Antibody treatment enhanced numbers, proliferation and IFN-γ expression of NK cells in developing tumors. The therapeutic effect was fully abrogated only after depletion of both, T cells and NK cells, or after ablation of either IFN-γ or TNF.ConclusionsTumor cell senescence may explain why patients responding to immune checkpoint blockade frequently show stable growth arrest of tumors rather than complete tumor regression. In the lymphoma model studied, successful therapy required both, tumor-directed T-cell responses and NK cells, which control, at least partly, tumor development through cytokine-induced tumor senescence.


2021 ◽  
Vol 11 ◽  
Author(s):  
Bonnie L. Russell ◽  
Selisha A. Sooklal ◽  
Sibusiso T. Malindisa ◽  
Lembelani Jonathan Daka ◽  
Monde Ntwasa

Through genetic and epigenetic alterations, cancer cells present the immune system with a diversity of antigens or neoantigens, which the organism must distinguish from self. The immune system responds to neoantigens by activating naïve T cells, which mount an anticancer cytotoxic response. T cell activation begins when the T cell receptor (TCR) interacts with the antigen, which is displayed by the major histocompatibility complex (MHC) on antigen-presenting cells (APCs). Subsequently, accessory stimulatory or inhibitory molecules transduce a secondary signal in concert with the TCR/antigen mediated stimulus. These molecules serve to modulate the activation signal’s strength at the immune synapse. Therefore, the activation signal’s optimum amplitude is maintained by a balance between the costimulatory and inhibitory signals. This system comprises the so-called immune checkpoints such as the programmed cell death (PD-1) and Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and is crucial for the maintenance of self-tolerance. Cancers often evade the intrinsic anti-tumor activity present in normal physiology primarily by the downregulation of T cell activation. The blockade of the immune checkpoint inhibitors using specific monoclonal antibodies has emerged as a potentially powerful anticancer therapy strategy. Several drugs have been approved mainly for solid tumors. However, it has emerged that there are innate and acquired mechanisms by which resistance is developed against these therapies. Some of these are tumor-intrinsic mechanisms, while others are tumor-extrinsic whereby the microenvironment may have innate or acquired resistance to checkpoint inhibitors. This review article will examine mechanisms by which resistance is mounted against immune checkpoint inhibitors focussing on anti-CTL4-A and anti-PD-1/PD-Ll since drugs targeting these checkpoints are the most developed.


Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1689 ◽  
Author(s):  
Edoardo Giannini ◽  
Andrea Aglitti ◽  
Mauro Borzio ◽  
Martina Gambato ◽  
Maria Guarino ◽  
...  

Despite progress in our understanding of the biology of hepatocellular carcinoma (HCC), this tumour remains difficult-to-cure for several reasons, starting from the particular disease environment where it arises—advanced chronic liver disease—to its heterogeneous clinical and biological behaviour. The advent, and good results, of immunotherapy for cancer called for the evaluation of its potential application also in HCC, where there is evidence of intra-hepatic immune response activation. Several studies advanced our knowledge of immune checkpoints expression in HCC, thus suggesting that immune checkpoint blockade may have a strong rationale even in the treatment of HCC. According to this background, initial studies with tremelimumab, a cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitor, and nivolumab, a programmed cell death protein 1 (PD-1) antibody, showed promising results, and further studies exploring the effects of other immune checkpoint inhibitors, alone or with other drugs, are currently underway. However, we are still far from the identification of the correct setting, and sequence, where these drugs might be used in clinical practice, and their actual applicability in real-life is unknown. This review focuses on HCC immunobiology and on the potential of immune checkpoint blockade therapy for this tumour, with a critical evaluation of the available trials on immune checkpoint blocking antibodies treatment for HCC. Moreover, it assesses the potential applicability of immune checkpoint inhibitors in the real-life setting, by analysing a large, multicentre cohort of Italian patients with HCC.


2020 ◽  
Vol 38 (5_suppl) ◽  
pp. 84-84
Author(s):  
Kushal Naha ◽  
Lakshmi Manogna Chintalacheruvu ◽  
Donald C. Doll ◽  
Sowjanya Naha

84 Background: Immune checkpoint blockade is known to be associated with various dermatologic adverse events. However, these adverse effects have not been studied in a systematic manner. This is especially relevant considering the rapidly increasing number of immune checkpoint inhibitors that are now available. Methods: We searched for eligible studies in PubMed and Google scholar. We reviewed randomized controlled trials involving cancer patients treated with immune checkpoint inhibitors - PD1 inhibitors, PDL1 inhibitors and CTLA4 inhibitors and for dermatologic adverse effects. A total of 47 randomized controlled trials involving 11875 patients met eligibility criteria for our study. Results: Incidence rate of all grade dermatologic adverse effects was 40.6% (95% confidence interval [CI], 39.4-41.7%). Most common adverse effects included pruritus (17.3%) (95% confidence interval [CI] 16.6-18.1%), undifferentiated rash (15.1%) (95% confidence interval [CI] 14.4-15.9%), vitiligo (3.6%) (95% confidence interval [CI] 3.2-3.9%), maculopapular rash (2.3%) (95% confidence interval [CI] 2.1-2.6%), stomatitis (0.7%) (95% confidence interval [CI] 0.55-0.92%) and dry skin (0.7%) (95% confidence interval [CI] 0.5-0.8%). Less common adverse events include palmoplantar erythrodysesthesia, pemphigoid skin reactions, lichen planus and hyperhidrosis. Grade 3 and higher adverse effects were seen in 1.3% of patients (95% confidence interval [CI] 1.1-1.6%). Conclusions: A wide range of dermatologic adverse effects can be seen with immune checkpoint blockade. While the majority of these events are of grade 1-2, they can occasionally be severe and even life threatening. Patients receiving immune checkpoint blockade should be closely monitored for dermatologic adverse effects.


2020 ◽  
Vol 1 (6) ◽  
Author(s):  
Federica Miglietta ◽  
Maria Silvia Cona ◽  
Maria Vittoria Dieci ◽  
Valentina Guarneri ◽  
Nicla La Verde

Although breast cancer is not traditionally considered an immunogenic type of tumor, the combination of immunotherapy and chemotherapy has recently emerged as a novel treatment option in triple-negative subtype in the advanced setting and other similar combinations of immune checkpoint inhibitors with chemotherapy are expected to become part of the neoadjuvant management in the near future. In addition, encouraging results have been observed with the combination of immune checkpoint blockade with diverse biological agents, including anti-HER2 agents, CDK 4/6 inhibitors, PARP-inhibitors. The present review summarized the available evidence coming from clinical trials on the role of immune checkpoint inhibitors in the management of breast cancer, both in advanced and early setting.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14078-e14078
Author(s):  
Qun Zhang ◽  
Lei Cheng ◽  
Jing Hu ◽  
Li Li ◽  
Mi Yang ◽  
...  

e14078 Background: Immune checkpoint inhibitors have brought great breakthroughs in cancer therapy. Activated immune response is known to be the prerequisite for exerting immunotherapy efficacy. Epstein-Barr virus (EBV) infection is associated with longer survival in gastric cancer (GC) patients due to enhanced anti-tumor immune response, and therefore it was reportedly played an important role in modulating immune checkpoint blockade therapy efficacy. However, molecular dimensions underlying the good response to immune checkpoint inhibitors in presence of EBV infection are still unclear. The aim of this study is to identify a gene signature related to EBV induced anti-tumor immune response, and select a tag gene from this signature to predict which patients are most likely to benefit from immune checkpoint blockade therapy. Methods: Two large transcriptome datasets from Gene Expression Omnibus(GEO) database (GSE51575 and GSE62254) were used to screen gene signature for EBV infected gastric cancer tissues. We further selected genes that showed a trend towards differential co-expression independent of EBV infection status. The tag gene of this differential co-expression signature was finally identified by bioinformatics analysis. To make an external validation, we performed RNA sequencing in 20 colorectal caner (CRC) tissues and 20 GC tissues, respectively. Meanwhile, tissue microarrays of CRC cohort (36 paired tumor and normal tissues) and GC cohort (75 paired tumor and normal tissues) were used to analyze the association of SLAMF8 with CD8 protein expression by immunohistochemistry (IHC). Results: Analysis of GEO datasets indicated 788 genes as feature gene cluster for EBV-positive gastric cancer, from which 290 genes were selected to be characterized by differential co-expression in either EBV-positive or EBV-negative gastric cancers. SLAMF8 was identified as the tag gene for this differential co-expression signature. This signature, tagged by SLAMF8, was successfully validated by our RNA sequencing data in presence of its good performance in dividing CRC and GC patients into two subsets. Moreover, we observed a significant association between SLAMF8 and CD8 expression in our CRC and GC tissue samples, in terms of either mRNA or protein level. Conclusions: SLAMF8, a potential indicator for T cell‐mediated immune response induced by EBV infection, may be served as a biomarker for individualized immune checkpoint blockade therapy in gastrointestinal cancer. Further SLAMF8 guided drug sensitivity tests are warranted to validate our results.


2017 ◽  
Vol 35 (6) ◽  
pp. 618-622 ◽  
Author(s):  
Naoshi Nishida ◽  
Masatoshi Kudo

With the development of molecular targeting therapy, several treatment options for advanced hepatocellular carcinoma (HCC) have become available in cases where curative and other palliative treatments, such as radiofrequency ablation, surgical resection, and transarterial chemoembolization, are not applicable. However, with the detection of a variety of mutations in cancer-related genes in a single tumor, molecular heterogeneity is commonly observed in HCC. Therefore, mutations in the major cellular signaling pathways underlie the development of resistance to molecular targeting agents. On the contrary, immune checkpoint inhibitors have proven effective in patients who are refractory to conventional treatments and molecular targeting therapy. Several clinical trials are currently investigating the efficacy of immune checkpoint inhibitors both individually and in combination with other types of anticancer agents. In this review, we focus on the potential of immune checkpoint blockade in the treatment of human HCC.


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